bpo-40715: Reject dict unpacking on dict comprehensions (GH-20292)
Co-authored-by: Lysandros Nikolaou <lisandrosnik@gmail.com>
Co-authored-by: Pablo Galindo <pablogsal@gmail.com>
(cherry picked from commit b8a65ec1d3d4660d0ee38a9765d98f5cdcabdef5)
Co-authored-by: Batuhan Taskaya <isidentical@gmail.com>
diff --git a/Grammar/python.gram b/Grammar/python.gram
index 9bf2697..a771abf 100644
--- a/Grammar/python.gram
+++ b/Grammar/python.gram
@@ -499,14 +499,16 @@
| '{' a=expression b=for_if_clauses '}' { _Py_SetComp(a, b, EXTRA) }
| invalid_comprehension
dict[expr_ty]:
- | '{' a=[kvpairs] '}' { _Py_Dict(CHECK(_PyPegen_get_keys(p, a)),
- CHECK(_PyPegen_get_values(p, a)), EXTRA) }
+ | '{' a=[double_starred_kvpairs] '}' {
+ _Py_Dict(CHECK(_PyPegen_get_keys(p, a)), CHECK(_PyPegen_get_values(p, a)), EXTRA) }
dictcomp[expr_ty]:
| '{' a=kvpair b=for_if_clauses '}' { _Py_DictComp(a->key, a->value, b, EXTRA) }
-kvpairs[asdl_seq*]: a=','.kvpair+ [','] { a }
-kvpair[KeyValuePair*]:
+ | invalid_dict_comprehension
+double_starred_kvpairs[asdl_seq*]: a=','.double_starred_kvpair+ [','] { a }
+double_starred_kvpair[KeyValuePair*]:
| '**' a=bitwise_or { _PyPegen_key_value_pair(p, NULL, a) }
- | a=expression ':' b=expression { _PyPegen_key_value_pair(p, a, b) }
+ | kvpair
+kvpair[KeyValuePair*]: a=expression ':' b=expression { _PyPegen_key_value_pair(p, a, b) }
for_if_clauses[asdl_seq*]:
| for_if_clause+
for_if_clause[comprehension_ty]:
@@ -657,6 +659,9 @@
invalid_comprehension:
| ('[' | '(' | '{') a=starred_expression for_if_clauses {
RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "iterable unpacking cannot be used in comprehension") }
+invalid_dict_comprehension:
+ | '{' a='**' bitwise_or for_if_clauses '}' {
+ RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "dict unpacking cannot be used in dict comprehension") }
invalid_parameters:
| param_no_default* (slash_with_default | param_with_default+) param_no_default {
RAISE_SYNTAX_ERROR("non-default argument follows default argument") }